Apparatus for helically crimping thermoplastic threads



J. BILLION Oct. 25, 1960 APPARATUS FOR HELICALLY CRIMPING THERMOPLASTICTHREADS Original Filed Feb. 17, 1954 INVENTORJ #44055 15/11 /0/1ATTORNEYS.

APPARATUS FOR HELICALLY CRIMPING THERMOPLASTKC THREADS Jacques Billion,21 Rue Puits Gaillot, Lyon, France Original application Feb. 17, 1954,Ser. No. 410,9625,

now Patent No. 2,881,504, dated Apr. 14, 1959. D1- vided and thisapplication Oct. 5, 1955, Ser. .No. 538,646

Claims priority, application France Feb. '24, 1953 1 Claim. (Cl. 28-1)The present invention relates to apparatus for imparting a helical crimpor deformation to thermoplastic threads to increase the flufliness ofthe threads themselves and of fabrics woven therefrom.

This application is a division of my copending-application, Serial No.410,968, filed on February 17, 1954, now US. Patent No. 2,881,504, for aProcess for Crimping Textile Threads.

When textile threads in general, and threads with continuous fibers inparticular, are made up into textile articles by knitting, weaving orthe like, they have the disadvantage of being relatively flat, withoutfirmness, and inelastic.

For this reason various attempts have been made in very manyapplications to improve this state of affairs and to impart moreelasticity, bulkiness or fiufliness and firmness to such threads, andconsequently to the fabrics or other articles made therefrom.

This result is usually obtained by imparting to the threads a hightwist, of the order of 2,000 to 3,000 turns per metre, for example.

These high twist threads are known as crepe threads.

But, although this creping or high twist process can easily be carriedout with certain threads, such as: silk, viscose rayon or wool, andgives good results, it cannot on the other hand be employed in normalworking conditions with certain other threads such as those of acetaterayon or those having a superpolyamidic base. It is said that thesethreads do not become creped.

In order to achieve a crepe state, attempts have been made to crepe thethread by a twist imparted in specific conditions, or withoutovertwisting it, by giving it a sinusoidal or helical configuration.

It is obvious that the helical shape or configuration, similar to thatof a cork-screw or a screw, deforms the thread in three dimensions andgives better results than the sinusoidal form, which deforms the threadonly in a plane or in two dimensions.

Various processes have been proposed for obtaining threads with ahelical crimp, but they are expensive and have never had advantageouspractical results.

The apparatus according to the present invention has as its object toimpart a helical crimped configuration to threads and to the filamentsof which they are composed, in order that the textile articles which areproduced from such helically crimped threads will have, amongst otherthings, a greater elasticity, a more resilient feel, a more flatteringand duller appearance, more bulkiness, and improved heat-insulatingproperties.

The process consists in winding a short longitudinal portion of thethread to be deformed effectively freely longitudinally movably at leastonce around a guide or support, in drawing it by one end whilemaintaining it thus wound, and in fixing the helical deformationproduced by said winding while said deformation is being producedprogressively throughout the length of the thread.

atent Q Patented Oct. 25, 1960 The accompanying diagrammatic drawingsillustrate, by 'way of example, apparatus for carrying said process into:effect:

Fig. l is a perspective view of a thread which has been subjected tothis process;

Fig. 2 shows a constructional form of apparatus for producing thedeformation;

Fig. 3 is a perspective view of an alternative threadfeeding apparatus.

In :the .illustration of Fig. 2, a 70 denier thread 2 having .a base ofpolyesters, formed of 36 filaments and having a twist of 30 turns permetre, is taken from a spinning bobbin 3.

The thread is drawn off this bobbin, passed over a grid-type .or othertensioning means 4 in order to give it va uniform tension, then it iswound 40 times around a .small metal shaft 5 which is 6 cm. long andwhich is preferably grooved helically over 4 cm. of its length up to 1cm. from each end by a groove 6 in the form of a screw-thread or regularhelix of 39 turns.

.At each rotation of the shaft the groove is advanced by 1 mm. Thisgroove is U-shaped and is /2 mm. wide and 1 mm. deep. The diameter ofthe shaft is 3 mm.

For initially placing the thread 2 in the groove 6, the shaft 5 mayrevolve freely on its two end portions, which are mounted in two smallbearings.

The small bearings are carried by the end walls 7 of a housing connectedto a heating plate 8 which is maintained at sufiicient temperature toenable the shaft around which the thread is wound to be kept at atemperature of C.

After passing slidingly along the bottom of the groove 6, and in sodoing turning 39 times around the shaft 5, the thread 2 is preferablydrawn at a constant speed of 12 meters per minute by the pulling rollermechanism of a thread-feeding device such as that of Fig. 3 laterdescribed herein, and is then received with reduced tension on a finalsupport element 13.

In order to wind the thread to which a helical configuration is to beimparted, an easy method consists in subjecting it to a tractive stressby the support (tube, reel, bobbin on which the treated thread is woundafter the operation (as shown in Fig. 2); in this case the support fromwhich the thread is taken should preferably oppose this tractive stresswith as constant as possible a force, but should not be driven itself.

This method, however, has the disadvantage that the thread arrives atand is wound on its support under considerable tension, so that thepressure of the thread turns one against the other partially destroysthe desired helical deformation which has just been imparted to thethread. In order to remedy this, it is proposed that the thread shouldbe passed, after the permanent fixing of the deformation, over therollers of a thread-feeding device (Fig. 3).

This thread-feeding device may be of standard type, such as those usedfor feeding the thread in doubling twisting frames. It may consist ofone or more rollers 10 and 11 revolving at a predetermined constantspeed, and on which the thread 2 executes a sufficient number of turnsfor it to be driven at the peripheral speed of the rollers without thepossibility of slipping or with very slight and constant slipping.

When it issues from the thread-feeding device the thread is received andwound onto the support 13 without any appreciable tension.

It has been observed that in order to carry out the process it wasnecessary to fix the deformations imparted to the thread by its twistedposition while such deformations were actually being produced.

The temperature should be as high as possible Without risking anydeterioration or injury of the textile fibres.

The speed at which the thread will be pulled and the fixed easily, andmore particularly to thermoplastic 3 ,threads.

The thread subjected to this process may be an untwisted thread or athread with negligible twist, for example, the twist received by thethread during spinning, but it may also have previously undergone atwisting, even a considerable twisting. It may also be a doubled thread,composed of threads of difierent size or nature as the case may be.

As will be obvious, the invention is not limited to the possibleembodiments which have been described in some detail hereinbefore, butit includes all other embodiments Within the scope of the claims forcarrying this method of deformation into efiect.

I claim:

Apparatus for imparting a helical deformation to a thermoplastic thread,said apparatus comprising a freely rotatable cylindrical guide memberhaving an external helical groove formed therein coaxially therewith,said external groove being adapted to receive a short longitudinalportion of said thread freely slidably therein whereby said portion ofsaid thread is maintained in a helical configuration during passagealong said groove, pulling means for drawing said thread progressivelyover said guide member through said groove whereby said cylindricalguide member is rotated, tensioning'means disposed ahead of said guidemember for imparting a substantially constant tension tosaid threadprior to and during its passage through said groove, and heating meansdisposed in proximity to said groove for heating said thread during thecourse of its passage over said guide member.

References Cited in the file of this patent UNITED STATES PATENTS1,625,983 Carter Apr. 26, 1927 2,216,142 Taylor et al. Oct. 1, 19402,244,832 Finlayson et al. June 10, 1941 2,319,077 McNally et'al May 11,1943 2,393,058 Pierce et al. Jan. 15, 1946 2,475,922 Stockly July 12,1949 2,797,529 Mohr et al July 2, 1957 FOREIGN PATENTS a 501,201 GreatBritain Feb. 23, 1939

